As snow settled on the silent New York Stock Exchange one recent Sunday, a nearby boutique was abuzz with activity. Inside the HermA s store, Pascale Mussard, the fifty-nine-year-old great-great-great-granddaughter of the saddle-maker Thierry HermA s, presided over the petit h Holiday Factory, where fans of the brand toiled at craft tables, in the presence of hundred-thousand-dollar handbags.